Plague was killing entire families thousands of years before the Black Death

New research published in Nature indicates that the deadly bacterium Yersinia pestis, responsible for the plague, was already causing widespread fatalities 5,500 years ago among small, mobile hunter-gatherer groups in East Siberia. This discovery, made by an international team of scientists, challenges previous assumptions that plague outbreaks were primarily associated with crowded urban environments.

By analyzing ancient DNA recovered from human remains at four burial sites, the researchers identified early forms of the plague bacterium and determined that these ancient strains were highly lethal. The analysis of the genetic relationships between the victims, along with archaeological and radiocarbon dating evidence, paints a clear picture of the devastating impact of these prehistoric outbreaks.

The findings suggest that some of the earliest known plague outbreaks may have been as deadly as later historical epidemics, particularly for children, even before the bacterium developed efficient flea-based transmission methods. The presence of a distinctive superantigen in the ancient strains further highlights the potential for severe inflammation and increased lethality.

These results support the theory that plague may have first emerged in Central or North-East Asia before spreading to other parts of Eurasia via populations of wild rodents, including marmots, which still carry the bacterium today.